If you need to assign different permissions to employees in your organization to access your CSS resources, IAM is a good choice for fine-grained permissions management. IAM provides identity authentication, permissions management, and access control.

If the current account has met your requirements, you do not need to create an independent IAM user for permission management. Then you can skip this section. This will not affect other functions of CSS.

With IAM, you can use your account to create IAM users for your employees and assign permissions to the users to control their access to your resources. IAM is free of charge. You pay only for the resources you purchase.

Permissions Management

New IAM users do not have any permissions assigned by default. You need to first add them to one or more groups and attach policies or roles to these groups. The users then inherit permissions from the groups and can perform specified operations on cloud services based on the permissions they have been assigned.

CSS is a project-level service deployed in specific physical regions. Therefore, CSS permissions are assigned to projects in specific regions and only take effect in these regions. If you want the permissions to take effect in all regions, you need to assign the permissions to projects in each region. When accessing CSS, the users need to switch to a region where they have been authorized to use cloud services.

You can use roles and policies to grant users permissions.

Roles are a type of coarse-grained authorization mechanism that defines permissions related to user responsibilities. There are only a limited number of service-level roles for granting permissions to users. When using roles to grant permissions, you need to also assign dependency roles. Roles are not ideal for fine-grained authorization and secure access control.
Policies are a type of fine-grained authorization mechanism that defines the permissions for performing operations on specific cloud resources under certain conditions. This mechanism allows for more flexible authorization. Policies allow you to meet requirements for more secure access control. For example, CSS administrators can only grant CSS users the permissions needed for managing a particular type of CSS resources.

Table 1 lists all the system-defined roles and policies supported by CSS.

Elasticsearch Administrator depends on the roles of other services to execute its permissions. Therefore, if you assign the Elasticsearch Administrator role to a user, assign its dependency roles at the same time.
CSS FullAccess and CSS ReadOnlyAccess can be used to control the resources that users can access. For example, if you want your software developers to use CSS resources but not delete them or perform any high-risk operations, you can create IAM users for these software developers and assign them only the permissions required for using CSS resources.

**Table 1** CSS system permission
Role/Policy Name	Type	Role/Policy Description	Dependency
Elasticsearch Administrator	System-defined role	Full permissions for CSS. This role depends on the Tenant Guest and Server Administrator roles in the same project.	Tenant Guest: A global role, which must be assigned in the global project. Server Administrator: A project-level role, which must be assigned in the same project
CSS FullAccess	System-defined policy	Full CSS permissions granted through policies. Users with these permissions can perform all operations on CSS. Some functions depend on corresponding permissions. To use certain functions, you need to enable the dependent permissions in the same project.	The VPCEndpoint Administrator system role is required for accessing a cluster through a VPC endpoint. Some operations depend on the following permissions: Automatically create an agency: iam:agencies:createAgency View the agency list: iam:agencies:listAgencies iam:permissions:listRolesForAgencyOnDomain iam:permissions:listRolesForAgencyOnProject iam:permissions:listRolesForAgency Display enterprise projects and predefined tags on the console: eps:enterpriseProjects:list tms:predefineTags:list Use the snapshot, word dictionary, and log management functions: obs:bucket:Get* obs:bucket:List* obs:object:List* obs:object:Get* obs:bucket:HeadBucket obs:object:PutObject obs:object:DeleteObject
CSS ReadOnlyAccess	System-defined policy	Read-only permissions for CSS. Users with these permissions can only view CSS data. Some functions depend on corresponding permissions. To use certain functions, you need to enable the dependent permissions in global services.	Some operations depend on the following permissions: View the agency list: iam:agencies:listAgencies iam:permissions:listRolesForAgencyOnDomain iam:permissions:listRolesForAgencyOnProject iam:permissions:listRolesForAgency Display enterprise projects and predefined tags on the console: eps:enterpriseProjects:list tms:predefineTags:list Use the snapshot, word dictionary, and log management functions: obs:bucket:Get* obs:bucket:List* obs:object:List* obs:object:Get* obs:bucket:HeadBucket

Table 2 lists the common operations supported by each system permission of CSS. Please choose proper system permissions according to this table.

**Table 2** Common operations supported by each system-defined policy
Operation	CSS FullAccess	CSS ReadOnlyAccess	Elasticsearch Administrator	Remarks
Creating a cluster	√	x	√	-
Querying a cluster list	√	√	√	-
Querying cluster details	√	√	√	-
Deleting a cluster	√	x	√	-
Restarting a cluster	√	x	√	-
Expanding cluster capacity	√	x	√	-
Adding instances and expanding instance storage capacity	√	x	√	-
Querying tags of a specified cluster	√	√	√	-
Querying all tags	√	√	√	-
Loading a custom word dictionary	√	x	√	Depends on OBS and IAM permissions
Querying the status of a custom word dictionary	√	√	√	-
Deleting a custom word dictionary	√	x	√	-
Automatically setting basic configurations of a cluster snapshot	√	x	√	Depends on OBS and IAM permissions
Modifying basic configurations of a cluster snapshot	√	x	√	Depends on OBS and IAM permissions
Setting the automatic snapshot creation policy	√	x	√	-
Querying the automatic snapshot creation policy	√	√	√	-
Manually creating a snapshot	√	x	√	-
Querying the snapshot list	√	√	√	-
Restoring a snapshot	√	x	√	-
Deleting a snapshot	√	x	√	-
Disabling the snapshot function	√	x	√	-
Modifying specifications	√	x	√	-
Scaling in clusters	√	x	√	-